-//===-- llvm/GlobalValue.h - Class to represent a global value ---*- C++ -*--=//
+//===-- llvm/GlobalValue.h - Class to represent a global value --*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file is a common base class of all globally definable objects. As such,
-// it is subclassed by GlobalVariable and by Method. This is used because you
-// can do certain things with these global objects that you can't do to anything
-// else. For example, use the address of one as a constant.
+// it is subclassed by GlobalVariable, GlobalAlias and by Function. This is
+// used because you can do certain things with these global objects that you
+// can't do to anything else. For example, use the address of one as a
+// constant.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_GLOBALVALUE_H
#define LLVM_GLOBALVALUE_H
-#include "llvm/User.h"
+#include "llvm/Constant.h"
+
+namespace llvm {
+
class PointerType;
+class Module;
-class GlobalValue : public User {
+class GlobalValue : public Constant {
GlobalValue(const GlobalValue &); // do not implement
+public:
+ /// @brief An enumeration for the kinds of linkage for global values.
+ enum LinkageTypes {
+ ExternalLinkage = 0,///< Externally visible function
+ LinkOnceLinkage, ///< Keep one copy of function when linking (inline)
+ WeakLinkage, ///< Keep one copy of named function when linking (weak)
+ AppendingLinkage, ///< Special purpose, only applies to global arrays
+ InternalLinkage, ///< Rename collisions when linking (static functions)
+ DLLImportLinkage, ///< Function to be imported from DLL
+ DLLExportLinkage, ///< Function to be accessible from DLL
+ ExternalWeakLinkage,///< ExternalWeak linkage description
+ GhostLinkage ///< Stand-in functions for streaming fns from BC files
+ };
+
+ /// @brief An enumeration for the kinds of visibility of global values.
+ enum VisibilityTypes {
+ DefaultVisibility = 0, ///< The GV is visible
+ HiddenVisibility, ///< The GV is hidden
+ ProtectedVisibility ///< The GV is protected
+ };
+
protected:
- GlobalValue(const Type *Ty, ValueTy vty, const string &name = "")
- : User(Ty, vty, name) {}
+ GlobalValue(const Type *Ty, ValueTy vty, Use *Ops, unsigned NumOps,
+ LinkageTypes linkage, const std::string &name = "")
+ : Constant(Ty, vty, Ops, NumOps), Parent(0),
+ Linkage(linkage), Visibility(DefaultVisibility), Alignment(0) {
+ if (!name.empty()) setName(name);
+ }
+
+ Module *Parent;
+ // Note: VC++ treats enums as signed, so an extra bit is required to prevent
+ // Linkage and Visibility from turning into negative values.
+ LinkageTypes Linkage : 5; // The linkage of this global
+ unsigned Visibility : 2; // The visibility style of this global
+ unsigned Alignment : 16; // Alignment of this symbol, must be power of two
+ std::string Section; // Section to emit this into, empty mean default
public:
+ ~GlobalValue() {
+ removeDeadConstantUsers(); // remove any dead constants using this.
+ }
- // getType - Global values are always pointers (FIXME, methods should be ptrs too!)
+ unsigned getAlignment() const { return Alignment; }
+ void setAlignment(unsigned Align) {
+ assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
+ Alignment = Align;
+ }
+
+ VisibilityTypes getVisibility() const { return VisibilityTypes(Visibility); }
+ bool hasHiddenVisibility() const { return Visibility == HiddenVisibility; }
+ bool hasProtectedVisibility() const {
+ return Visibility == ProtectedVisibility;
+ }
+ void setVisibility(VisibilityTypes V) { Visibility = V; }
+
+ bool hasSection() const { return !Section.empty(); }
+ const std::string &getSection() const { return Section; }
+ void setSection(const std::string &S) { Section = S; }
+
+ /// If the usage is empty (except transitively dead constants), then this
+ /// global value can can be safely deleted since the destructor will
+ /// delete the dead constants as well.
+ /// @brief Determine if the usage of this global value is empty except
+ /// for transitively dead constants.
+ bool use_empty_except_constants();
+
+ /// getType - Global values are always pointers.
inline const PointerType *getType() const {
- return (const PointerType*)User::getType();
+ return reinterpret_cast<const PointerType*>(User::getType());
}
+ bool hasExternalLinkage() const { return Linkage == ExternalLinkage; }
+ bool hasLinkOnceLinkage() const { return Linkage == LinkOnceLinkage; }
+ bool hasWeakLinkage() const { return Linkage == WeakLinkage; }
+ bool hasAppendingLinkage() const { return Linkage == AppendingLinkage; }
+ bool hasInternalLinkage() const { return Linkage == InternalLinkage; }
+ bool hasDLLImportLinkage() const { return Linkage == DLLImportLinkage; }
+ bool hasDLLExportLinkage() const { return Linkage == DLLExportLinkage; }
+ bool hasExternalWeakLinkage() const { return Linkage == ExternalWeakLinkage; }
+ void setLinkage(LinkageTypes LT) { Linkage = LT; }
+ LinkageTypes getLinkage() const { return Linkage; }
+
+ /// hasNotBeenReadFromBitcode - If a module provider is being used to lazily
+ /// stream in functions from disk, this method can be used to check to see if
+ /// the function has been read in yet or not. Unless you are working on the
+ /// JIT or something else that streams stuff in lazily, you don't need to
+ /// worry about this.
+ bool hasNotBeenReadFromBitcode() const { return Linkage == GhostLinkage; }
+
+ /// Override from Constant class. No GlobalValue's are null values so this
+ /// always returns false.
+ virtual bool isNullValue() const { return false; }
+
+ /// Override from Constant class.
+ virtual void destroyConstant();
+
+ /// isDeclaration - Return true if the primary definition of this global
+ /// value is outside of the current translation unit...
+ virtual bool isDeclaration() const = 0;
+
+ /// getParent - Get the module that this global value is contained inside
+ /// of...
+ inline Module *getParent() { return Parent; }
+ inline const Module *getParent() const { return Parent; }
+
+ /// removeDeadConstantUsers - If there are any dead constant users dangling
+ /// off of this global value, remove them. This method is useful for clients
+ /// that want to check to see if a global is unused, but don't want to deal
+ /// with potentially dead constants hanging off of the globals.
+ void removeDeadConstantUsers();
+
// Methods for support type inquiry through isa, cast, and dyn_cast:
- static inline bool classof(const GlobalValue *T) { return true; }
+ static inline bool classof(const GlobalValue *) { return true; }
static inline bool classof(const Value *V) {
- return V->getValueType() == Value::MethodVal ||
- V->getValueType() == Value::GlobalVariableVal;
+ return V->getValueID() == Value::FunctionVal ||
+ V->getValueID() == Value::GlobalVariableVal ||
+ V->getValueID() == Value::GlobalAliasVal;
}
};
+} // End llvm namespace
+
#endif
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